Screenshots

Showing back face and front face culling.  This is needed for Kruger's method of rendering volumes using two passes.  The first renders the texture coordinates of the front faces into a texture.  Then in the second pass a fragment shader runs for each fragment in the back faces.  It uses the difference between the texture coordinates of the back and front faces to form a ray.  The ray can then iterate through the dataset to render a volume.
Showing back face and front face culling. This is needed for Kruger's method of rendering volumes using two passes. The first renders the texture coordinates of the front faces into a texture. Then in the second pass a fragment shader runs for each fragment in the back faces. It uses the difference between the texture coordinates of the back and front faces to form a ray. The ray can then iterate through the dataset to render a volume.